There are many patients suffering from hemorrhoidal diseases such as hemorrhoids (internal hemorrhoid, external hemorrhoid) and anal fissure, and other anal diseases, and many of these diseases associated with inflammation, severe pain and/or pruritus.
Nowadays as agents for treating hemorrhoidal diseases, a suppository and an ointment containing a local anesthesia, a steroid, an antihistamine, etc. are used, but administration of the local anesthesia or the external steroid often causes to delay of the wound healing and there is a possibility that systemic side effect may occur.
Furthermore, in general as to administer a nonsteroidal antiinflammatory agent to the mucosal injured legion causes to delay of the remedy of said lesion, it is considered to be contraindication.
In regard to therapy of hemorrhoidal diseases and other anal diseases, the preparations in which the drugs having their effects respectively are contained, have been patiently used even if these drugs extend the therapeutic time.
By the way, from of old acetylsalicylic acid (it may be written as aspirin.) has been widely used as an antipyretic analgesic agent mainly in oral administration form as it has potent analgesic activity, antifebrile activity and antirheumatic activity. Aspirin is safe as its side effect is less.
Recently the external application of acetylsalicylic acid has been studied.
Furthermore, as a new use of acetylsalicylic acid in the form of an external preparation, ointments for treating neuralgia (Japanese Patent Publication A3-72426), external preparations for treating skin injury (Japanese Patent Publication A9-235232), a transdermal administration system for treatment of thrombosis and for prophylactic treatment of cancer (Japanese Patent Publication Tokuhyo 8-504198), external preparations for treating allergic dermatitis (Japanese Patent Publication A11-373511) and external preparations for treating pruritus (WO 01/47525) are illustrated.
However, the external preparation containing acetylsalicylic acid in order to treat hemorrhoidal diseases and other anal diseases and in order to restrain pain and/or pruritus associating with their diseases has not been reported.